This invention relates to an optical switch for a fiber optic network.
Optical switches can be used in optical networks to switch light beams from input optical fibers to output optical fibers. A mirror substrate is provided having a plurality of input pivoting mirrors and output pivoting mirrors thereon. A respective input pivoting mirror is located in a path of a respective light beam being propagated by a respective input optical fiber. The input pivoting mirror is pivotable relative to the mirror substrate to alter an angle at which the light beam is reflected therefrom. The angle is controlled so that the light beam falls on a respective output pivoting mirror in line with a respective output optical fiber to which the light beam is to be switched. The output pivoting mirror then reflects the light beam and is pivoted so as to ensure that the light beam is propagated in a direction in which the output optical fiber extends, to ensure coupling of the light beam into the output optical fiber.
Proper functioning of such a switch depends on correct functioning of the input pivoting mirrors and the output pivoting mirrors. No diagnosis or control of the switch can be carried out if there is no feedback that indicates how the pivoting mirrors function. Other applications may exist for the ability to monitor operation of a switch.
An optical switch is described comprising an input optical fiber, a mirror substrate, an input pivoting mirror, an output optical fiber, a first optical splitter, and a first optical detector. The input optical fiber propagates a light beam. The mirror substrate is secured to the housing. The input pivoting mirror is located in a path of the light beam after leaving the input optical fiber. The input pivoting mirror is pivotally secured to the mirror substrate. Pivoting of the mirror relative to the mirror substrate alters an angle with which the light beam is reflected therefrom. The output optical fiber has an end through which the light beam enters after being reflected by the input pivoting mirror. The first optical splitter is located in a path of the light beam after that signal leaves the input optical fiber. The first optical splitter splits the light beam into a first propagated portion and a first monitoring portion. The first propagated portion is propagated through the output optical fiber and the first monitoring portion is detected by the first optical detector.
Other features and advantages of the present invention will be apparent from the accompanying drawings and from the detailed description that follows below.